Barking drum



Oct. 28, 1930. J. STRINDLUND BARKING DRUM 4 Sheets-Shet 1 Filed July 16,1928 J. STRINDLUND 1,779,568

BARKING DRUM Oct. 28, 1930.

Filed July 16, 1928 4 Sheets-Sheet 2 [oven/0r Ja/m sfrl'n dlandH/lornev.

Oct. 28, 1930. J. STRINDLUND BARK IN G DRUM Filed July 16, 1928 4Sheets-Sheet 5 In ven/ar':

V M /w d W H M mw 0 W h J. STRINDLUND Oct 28, 1930.

BARKING DRUM Filed July 16, 1928 tweets-sheet 4 mm w 1 In van/07 7015/7J/nnd/una' fiy Patented Oct. 28, 1930 JOHN STBINIDLUND,

PATENT OFFICE OF TOFTE, NORWAY BARKING nn'om Application filed July 16,1928, Serial No The present invention relates to an imprevement inbarking drums of the type which rotate partially submerged in water, andwhich are provided on their inner sides with ribs or the like whichduring the rotation of the drum catch and lift the logs in the drum andthen allow them to fall, each such drum being supported by two endlesschains each of which runs around the drum and also over a chain-wheel.

The invention resides principally in that each chain-wheel is adjustablymounted in the vertical direction forthe purpose of rendering possibleadjustment of the position of the drum in the vertical directionaccording as the chain's become worn. Preferably, one of saidchain-wheels also servesas a driving wheel for the drum, being for thispurpose connected to a suitable driving device. This arrangementprovides a very simple and reliably operating barking drum.

In the accompanying drawings a few embodiments of the invention isillustrated by way of example. Fig. 1 shows a side view of a barkingdrum according to the invention, Fig. 2 shows a top plan view of thedrum, and Fig. 3 shows an end view of the drum. In Figs. 1 and 2 thedrum is shown with less than its proportional length, for want of space.Fig. 4shows to a larger scale a detail view of the ribs provided on theinside of the drum. Fig. 5 shows an end view of a slightly modifiedconstruction of a barking drum.

The barking drum illustrated consists of two separate drums 1, which areplaced in alignment andclose to one another so that they operate as asingle barking drum. The drums may be constructed, for instance, of barsor ribs 2 of heavy sheet iron which are riveted to the insideof rings 3of channel iron, and are spaced apart so as to form longitudinal slots 4between said bars, through which slots the water may flow in and outwhen the drums are caused to rotate'partially submerged in a tank 5containing water.

Each drum is supported by two endless chains 6, each of which runsaround the drum between two guide rings 7 and over a single chain-wheel8, hich suitably should have a w less diameter than the drum. Eachchain- 293,114, and in Sweden February 5, 1927.

wheel 8 is rotatably journalled in a lever 9, which is pivoted at oneend on a horizontal shaft 10 and is supported at the other end by atackle block 11 by means of which the lever, and thus also thechain-wheel 8 journalled therein, may be raised and lowered. In theconstruction illustrated in Figs. 1 to 3, one of the two chain-wheels 8which support each drum 1, serves simultaneously as a driving wheel, andis for this purpose driven through a toothed gearing 12 by anintermediate shaft 13. which in its turn is driven by means of a chain Hfrom a main shaft 15 common to both drums and which is driven by meansof a pulley 16 from a suitable motor, not illustrated in the drawing.The drums l are guided by guide rollers 17 which are rotatably mountedat both sides of the Water tank 5. The guide rollers on one side of thetank may suitably be adjustable in the vertical 7 direction, asindicated in Fig. 3..

The ribs 18 provided on the inside of the drums are formed by the sheetiron bars 2, which form the drums 1, being bent at one side-namely atthe front side as taken in the direction of rotation of the druminwardsand then slightly backwards, in the manner illustrated in Fig. 4. Inthis manner the ribs obtain rounded edges 19 against which the logsstrike during the rotation of the drum, and since the ribs are also madesomewhat resilient the shocks will bemoderated, so that splittingand'crushing of the ends of the logsis avoided as far as possible. Thetwo drums 1 are so dimensioned that their total length is at least 7.5times as large as the drum diameter, which latter is chosen as small asit is possible to do for practical reasons. The speed of rotation of thedrum is so chosen that the peripheral speed does 91 not exceed 1.2meters per second. With these dimensions the height of vfall of the logswithin the drum, and thus also the violence of the impact of the logsagainst the ribs becomes as small as possible, so that the logs 95 willnot be damaged. Since the entire weig the logs within 6, the friction tof the drums and of the drums rests on the chains between the drums andthe chains, .as well as the friction between the Y required the drumshould chains and the driving-chain-wheels 8 becomes so great that noteeth or the like are The Vertically adjustable mounting of thechain-wheels 8 also provides the advantage that it is easy, by means ofthe tackle blocks 11, to adjust the position of the drums in thevertical direction according as the chains become worn.

During the rotation of the drum the logs gather mainly on that side ofthe drum where its periphery moves upwards, that is to say, on theleft-hand side in Fig. 3. This results in the common centre of. gravityof the drum and logs being moved towards the same side,

which in'its turn causes the necessary supporting force to becomegreater at this side than at the opposite side of the drum. In order toavoid unnecessarily high stresses in the chains 6, the left-hand partsof the same, which move upwards in Fig. 3, should be Vertical orapproximately vertical. At the same time the friction between the chainsand the wheels 8 and between the chains and be as great as possible, andin order to gain this end it is desirable that the tension in the twoparts of each chain shall be as nearly drum has its greatest speed andits greatest load. For this purpose the chain-wheels 8 are given a lessdiameter than the drum, so that the descending parts of the chains 6 tothe right in Fig. 3will move in a direction inclined to the verticalline. By this arrangement a tension will be set up in these parts of thechains which is greater than the vertical load on this side, suitableinclination of said descending chain parts it is possible to obtain atension as nearly equal as possiblein the two parts of each chain.

During the operation'of the barking drum there will as a rule be a morevconcentrated bark mixture within the drum than outside the same in thewater tank 5. In order to avoid this, there are secured to the outsideof the drums 1.0ne or more bodies 20 which effect a stirring o I thewater during the rotation, whereby it becomes easier for the bark toflow out through the slots 4. The rubbing 0r friction between the logswill also become more powerful, so that it is possible to decrease thequantity of water used, which is of particular importance in those caseswhen hot water is used. I

The construction illustrated in Fig. 5 difffers from that abovedescribed mainly in that the chain-wheels 8' on the levers 9' and whichsupport the drum 1' by means of the chains 6', are not utilized asdriving members. Instead, there are provided special chain drivingwheels 21 which engage the ascending parts of the chains 6', said wheels21 bein wheels 22 which in t eir turn are driven by or causing the drumsto rotate.

equal as possible when the and by choosing a whichare j ournalledconnected to chain-' .means of chains 23 from chain-wheels 24 on themain shaft 15'.

he embodiments above described and illustrated in the drawings are onlyto be regarded as examples of the invention, as it will be understoodthat the same may be further modified in respect to their details inseveral ways without departing from the principle and scope of theinvention. For instance, the shape of the ribs 18 may be changedas'desired to suit various requirements, and said ribs may also be madeas separate parts and be secured in suitable manner, for instance bymeans of rivets, to the inside of the drum. In certain cases it may besuitable to provide one or more rods or tubes within the drumsdiametrically through the same, for instance in the manner indicated bydotted and dashed lines in Fig. 3, said rods or tubes serving to effecta better stirring of the logs during the rotation of the barking drum.

I claim: 1. In a barking drum, the combination of a drum, two endlesschains running around and supporting said drum, and a single chain wheelfor each of said chains supporting the same, each such chain having itsascending part running in a substantially vertical direction and itsdescending part running in an inclined direction, each chain wheel beingadjustable in the vertical direction.

In a barking drum, the combination of a drum, two endless chains runningaround and supporting said drum, a single chain wheel for each of saidchains supporting the same, each such chain having its ascending partrunning in a substantially vertical direction and its descending partrunning in an inclined direction, each chain wheel being adjustable in te vertical direction, and means or driving one of said chain wheels.

3. In a barking drum, the combination of a drum, two endless chainsrunning around and supporting said drum, a single chain wheel for eachof said chains supporting the same, each such chain having its ascendingpart running in a substantially vertical direction and its descendingpart running in an inclined direction, a lever for each chain wheel onwhich such wheel is rotatably mounted,

said lever being pivoted at one end, and

end of said lever.

same, each such chain having its ascending part running in asubstantially vertical direction and its descending part ru ing in aninclined direction, a lever for each chain wheel on which such wheel isrotatabl mounted, said lever being pivoted at one en means for verticaladjustment of the other end of said 1ever,and of said chain wheels.

5. In a barking drum, the combination of a drum, ribs on the inside ofsaid drum, said ribs being resilient and having rounded edges, twoendless chains running around and supporting said drum, and 'a singlechain wheel for each of said chains supporting the same, each such chainhaving its ascending part running in a substantially vertical directionand its descending part running in an inclined direction, each chain vwheel being adjustable in the vertical direction.

6. In a barking drum, the combination of a drum, a water tank in whichsaid drum is submerged, two endless chains running around and supportinsaid drum, a single chain wheel for each 0 said chains su porting thesame, each such chain having its ascending part running in asubstantially vertical direction and its descending part running in aninclined direction, eachchain wheel being adjustable in the verticaldirection, and a stirring body secured to the outside of said drum. 4

' JOHN STRINDLUND:

means for driving one

